Graphene nanoplatelets have been shown in idealized experiments to enhance a variety of important functional properties of commercially important polymers. For instance, polymer-graphene nanocomposites demonstrate enhanced mechanical properties, electrical conductivity, thermal conductivity, gas/vapor barrier properties, and flame retardency. Accordingly, polymer-graphene nanocomposites consisting of a graphene dispersed in a polymer matrix have been the subject of much research and development activity in recent years. While a significant number of polymer nanocomposites of this type have been developed and/or commercialized, conventional polymer nanocomposites suffer from limitations related to suboptimal exfoliation and dispersion of the graphene in the polymer matrix that attenuates these desirable performance attributes. For example, when graphene in powder form is melt blended with polymers using extruders and conventional fillers under typical compounding conditions, the resultant composites exhibit suboptimal exfoliation and dispersion of the graphene in the polymer matrix. As a result, the materials have performance characteristics that are far below a theoretical magnitude of performance enhancement predicted to be provided by the graphene. Technologies have been developed to produce highly exfoliated solutions, dispersions, slurries, or wet cakes by solvent exfoliation of graphene using solvent systems. Though these materials can be co-dispersed with polymer solutions or polymer dispersions, followed by removal of the solvent to produce polymer nanocomposites with improved exfoliation and dispersion of the nanomaterial, the performance attributes of these composites are also typically below theoretical levels due to incomplete exfoliation and dispersion of the nanomaterial.